1. Field of Art
The disclosure generally relates to the field of memory devices, and more particularly, generation of virtual memory devices.
2. Description of the Related Art
Secure Digital (SD) cards are in wide use for many storage applications. They are most commonly used to store audio (MP3 players), pictures (digital cameras), and full motion video (camcorders and HD camcorders). The SD card provides an acceptable portable storage medium to transfer unprotected content between different devices, especially for the video capture devices mentioned above. The content stored on SD cards can be transferred or archived to devices with larger storage capacities and additional processing capabilities. One such additional processing capability allows consumers to create and manage a digital archive of consumer generated content.
Consumers are familiar with the SD card's basic storage capabilities, but they are mostly unaware of its security features (the S in Secure Digital). This is because there are very few applications that use this advanced functionality. Applications that use the security features primarily enable digital rights management (DRM) to protect commercial content from copying or other forms of piracy. Examples of DRM applications include still images (Gallery Player) and full-motion video (1-seg and GreenPlay). The DRM protection must remain intact during content loading, transfer, and archival. Maintaining protection through transfers from SD card to other memories cannot be archived easily. While an SD card is suited for content loading and transfer, it is not as well suited for the archival aspect.
SD cards are suited to content loading, purchasing and transporting content, but not for creating a digital library. The main reasons correspond to the primary use of SD cards as a portable storage medium. Accordingly, the size, cost, and the lack of labeling on the SD card result in an undesirable format for a digital library. Although SD cards are available currently in up to 64 gigabyte (GB) capacity, a typical digital rights management (DRM)-protected commercial video is approximately 2 GB. Therefore, only 32 DRM-protected commercial videos can be stored on any single SD card. Multiple SD cards are required in order to create a digital library of any significant capacity. In contrast, hard disk drives are in abundant supply in sizes ranging from several hundred gigabytes to few tens of terabytes. These allow for storing upwards of 5000 DRM-protected commercial videos at roughly the same price as a 32 GB SD card.
The DRM used by SD cards, content protection for recordable media (CPRM), allow for content to be moved and/or copied to other CPRM-compliant devices because the anti-piracy mechanism is maintained, but technical challenges have prevented this. First, the CPRM license agreement specifies the process requirements for moving content to/from the SD card, but does not specify the file formats for the non-SD card device. In addition, file structures and data to implement the DRM are complex and have many entities. A typical secure exchange to move or copy content may require a minimum of 150 secure operations for the DRM portion alone. Maintaining the complex relationships within a new file structure presents a substantial processing and memory resource challenge in addition to the effort of developing software code to maintain and manage the process.
Second, security software is only defined for personal computer (PC) architectures. It is not defined for other software or hardware architectures, including many devices which utilize SD cards that must maintain DRM protection through the transfer and viewing processes such as mobile phones, TV, set top boxes, and Blu-ray disc players and the like.
Third, many devices may not implement an internal SD card for a variety of reasons including cost, space considerations for connectors, and the aforementioned lack of security software drivers. Alternatively, these devices include dedicated flash for storage applications, but lack the security feature included within the SD card. Thus, these devices are unsuitable for storage according to the DRM requirements.
Conventional external storage does not support securely storing data. A few proprietary solutions exist, but no standardized solution is available apart from SD cards because there has not been a consumer requirement for secure external storage.